1. Field of the Invention
The present invention relates to a method and apparatus for cooling and preparing a beverage. Particularly, the present invention includes a method and apparatus for cooling water with ice to produce an outflow of cooled water and for cooling beverage concentrate with ice to produce an outflow of cooled beverage concentrate, and then mixing the two outflows in proper proportion.
2. Description Of Related Art
Beverage dispensers are commonly used in restaurants and convenience stores to mix a beverage concentrate with either carbonated or non-carbonated water, and to cool the mixed beverage. Beverages are typically considered to before refreshing when served cold. Therefore, the quality of the mixed beverage that is produced is at least partially dependent upon the temperature at which the mixed beverage is dispensed. If carbonated water is used, the quality of the mixed beverage is further enhanced by obtaining and maintaining a high level of carbonation in the water, and by minimizing the amount of flashing or foaming that occurs when the carbonated water and beverage concentrate are mixed. Since solubility of carbon dioxide is inversely related to temperature, a high level of carbonation can be obtained and maintained by reducing the temperature of the water prior to carbonation and by maintaining the reduced temperature of the water after carbonation, respectively. Likewise, foaming is minimized by reducing the temperature of the beverage concentrate to a temperature approximately equal to that of the carbonated water prior to mixing.
One of the most popular cooling devices to date is referred to as a cold plate. A cold plate conventionally includes a large block of aluminum, perhaps 20 inches square and 4 inches high. Mounted within the aluminum block are a series of horizontally coiled stainless steel tubes or other conduits stacked vertically above each other. Each stainless steel tube respectively carries a different liquid, such as water or a beverage concentrate. If carbonation is desired, a separate carbonator is provided.
To cool the liquids, ice is provided in contact with the upper surface of the cold plate while each of the different liquids for the beverage are flowed through a respective tube. The melt runoff from the ice is drained and discarded.
Hence, the water and beverage concentrates are cooled by heat transfer through the walls of the stainless steel tube and the aluminum block. After passing through the cold plate, the water and a selected beverage concentrate are mixed in proper proportion and dispensed from a dispensing valve located downstream of the cold plate. The cold plate is often provided in the bottom of a large container or tank that is mounted in or on a counter top. The cold plate provided an advance over prior arrangements which cooled water and beverage concentrates by flowing those fluids through unencased conduits in an ice water bath.
Although the cold plate may adequately cool the water and beverage concentrate, it is an expensive and heavy component. These high costs are partially due to the quantity of aluminum required to construct the large solid block, as well as the complexity of fabricating a series of tubes within the block while ensuring that no leaks occur. The size and weight of the cold plate also increases costs and difficulty in constructing, handling, and shipping dispensers using this cooling system.
The cold plate also has cooling inefficiencies. The efficiency of the cold plate is inherently dependent upon the heat transfer rate between the ice and the liquid to be cooled. Therefore, when the concentrate tubes are encased in the aluminum block, several walls of aluminum and stainless steel separate the ice and the liquid to be cooled, and the heat transfer rate decreases accordingly. Hence, the tube located closest to the upper surface of the cold plate will be cooled most, while the tube located furthest from the upper surface will be cooled least. In view of this, the liquid required most, which is typically carbonated or non-carbonated water, is prearranged to flow through the top tube of the cold plate, while the liquid required least flows through the bottom tube of the cold plate.
Since only a limited length of tubing can extend through the cold plate, efficiency also is dependent upon the duration in which the liquid to be cooled is held within the cold plate. During periods of peak demand, it is evident that the liquid, particularly carbonated or non-carbonated water, will pass through the cold plate much more quickly than during periods of low or casual demand. Therefore, the duration in which the liquid passes through the cold plate during peak demand may be inadequate for sufficient cooling to occur. There also can be a cooling problem when demand is low. The liquid that has already passed through the cold plate and is held in the portion of the tube between the cold plate and dispensing valve will not remain cooled for an extended period of time. Therefore, drinks dispensed during periods of casual demand often are unsatisfactorily cooled.
An additional concern related to the cold plate is the adverse impact on the environment due to draining and discarding of the melt runoff from the ice or ice/water mixture. Severe droughts and water shortages are recurring throughout numerous areas of the country and the world. Since beverage dispensers are so widely used, the melt runoff discarded by beverage dispensers significantly wastes a valuable natural resource.
Another conventional cooling apparatus is referred to as a counter electric. The counter electric utilizes refrigeration to freeze water surrounding a series of tubes, each carrying a different liquid to be cooled. However, this device must rely on a refrigeration unit and is not capable of dispensing ice into the drink in the typical commercial manner.
As such, there remains a need for a method and apparatus for more efficiently cooling, preparing, and dispensing a cool beverage without wasting water and electricity. Additionally, there remains a need for reducing the cost, size, and weight of an apparatus for cooling, preparing, and dispensing a cool beverage.